The present invention relates to a sport device, and particularly, to a sport device with extendable and retractable sport members.
It is well known that sports are necessary for good physical body tone. Sport is needed for well-being of one's health. Some sports which are very conducive to achieve these purposes are running and skating at high speed, such as roller skating, ice skating and the like.
A number of skating devices have been proposed in the art and are in daily use. Attempts have been made to make such sport devices with extendable and retractable sport members. It appears, however, that the known sport devices of the above type are not yet ultimate with respect to their convertibility and strength in an extended or a retracted position. Especially in the extended position the sport members are subject to increased forces whose magnitude depends on the level of activity of the user, on the speed at which he or she moves, and on the weight of the user. Thus, the known sporting devices are quickly worn out at active sports and thereafter lose their reliability. It also happened that competitors lost in competitive sports events due to inadequate functioning, fastening or reliability of their sport devices. The known sports devices do not have means for moving the sport members between the extended and retracted positions without the aid of the hands of the user.